Plain relieving attachment for lathes



Nov. 18, 1924. 1,516,196

A. B. LINDSTROM PLAIN RELIEVING ATTACHMENT FOR LATHE-S v Fil ed Feb. 271922 Patented Nov. 18, 1924.

PATENT OFFICE.

UNITED SE AUGUST BERNHARD LINDSTROM, O'F HARTFORD, CONNECTICUT, ASSIGNORTO PRATT & WHITNEY COMPANY, OF NEW YORK, N. Y., A CORPORATION OF NEWJERSEY.

PLAIN RELIEVING ATTACHMENT FOR LATHES.

Application filed. February 27, 1922. Serial No. 539,524.

To all whom it may concern:

Be it known that I, AUGUST BERNHARD LINDSTROM, a citizen of the UnitedStates, residing at Hartford, in the county of Hartford and State ofConnecticut, have invented certain new and useful Imp-rovements in PlainRelieving Attachments for Lathes, of which the following is aspecification.

This invention relates to lathes and particularly to an improvedrelieving attachment therefor. It is the primary object of the inventionto provide such an improved mechanism easily applicable to an ordinarylathe and particularly adapted to perform exterior and interiorrelieving operations upon various kinds of work, such as millingcutters, hobs, taps, dies, reamers, etc. In a copending applicationSerial No. 609,- 030 is illustrated a lathe provided with an improvedrelieving attachment. Reference to such application should be made for afull illustration and description of the general lathe structure whichwithin itself comprises no part of the present invention and istherefore not illustrated herein.

It is an object of the invention to provide a relieving attachmentcomprising a rotary cam adapted to move along the lathe bed with thetool carriage and cam follower means connected to the tool slide andopera tive on either side of the cam whereby to operate the tool slidein either direction for performing either exterior or interior relievingoperations.

It is another object of the invention to provide a mechanism of theabove type comprising a rotary cam, a pair of cam followcrs respectivelyat opposite sides of the cam. and means whereby either follower may beplaced in operative engagement with the cam to operate the tool slide ineither direction for performing either exterior or in terior relievingoperations, hand operated means also being provided in connection withthe mechanism for moving and holding both cam followers disengaged fromthe cam thereby releasing the mechanism from operation even though thecam continues to rotate.

A further object of the invention is to provide a mechanism of the abovetype in connection with a former bar at the rear of the lathe bed, thetool slide being operatively connected to the former bar and relievingmechanism whereby the work is given the shape of the former and relievedby the relieving mechanism.

WVith the above and other objects in View, my invention consists in thefeatures of construction and operation set forth in the followingspecification and illustrated in the accompanying drawing. In suchdrawing annexed hereto and forming a part of this specification, I haveshown one embodiment of my invention as applied to the bed and toolcarriage of a lathe, but it will be understood that the invention can beotherwise embodied and that the drawing is not to be construed asdefining or limiting the scope of the invention, the claims appended tothis specification being relied upon for that purpose.

Referring to the figures of the drawing:

Figure 1 is a plan View of the attachment as applied to a. lathe.

Fig. 2 is a side view thereof partially in section on line 22 of Fig. 1.

Fig. 3 is a rear end elevation.

Fig. 4 is a cross section thereof on line t4 of Figs. 1 and 2.

Fig. 5 is a side elevation of the relieving mechanism.

Fig. 6 is a detail bar.

I11 the drawing, 1 indicates the bed of a lathe, 2 the tool carriageslidable on the ways 3 thereof, 1 a taper slide on the carriage, 5 atool slide on the taper slide, and 6 a tool support slidably mounted onthe tool slide 5. A screw 7 journaled in the taper slide operativelyengages a nut 8 0n the tool slide 5 whereby the latter can be adjusted.The tool support 6 can be adjusted on the tool slide 5 by the usualscrew handle 9.

A former or taper bar 10 is mounted in a guide 11 on a bracket 12secured to the bed. The bar is provided with a yokeshaped portion 13 onwhich is seated and secured by a pin 14:, one end of a boxlike housing15. The other end of this housing is slidably mounted on the taperslide, as illustrated in Fig. 4. The housing is furthermore providedwith a pair of projecting ears 16 having arcuate slots 17 through whichproject tap bolts 18 whereby to secure the housing to the taper bar inany angular position of the latter.

A rotary cam 19 is mounted on a shaft 20 plan view of the formerjournaled in the housing 15, this shaftbeing driven from the headstockgearing in the usual manner. One specilic form of drive for this shaftis fully illustrated in the above mentioned copending applicatioi'i, itbeing sufficient for the present invention however to state that thisshaft is driven from the headstock spindle in the usual manner. A block21. is mounted for reciprocation transversely of the shaft in thehousing. This block is provided with two cam followers 2:2 and 2%}respectively on opposite sides of the cam. A bolt 2t extends verticallythrough the block and taper slide whereby the taper slide is secured tothe block, the bar 10 being recessed transversely at to pern'iitmovement of these elements transversely thereof.

Spring means for normally keeping one of the cam followers inengagen'ient with the am is preferably mounted in the block 21. Theblock is preferably provided with a pair of such spring means onopposite sides of the cam, such means being mounted in bores 26 in theblock. The construction in each bore being identical, a description ofone will suiiice. Each bore comprises two outer portions having anannular shoulder QT therebetween, a smaller opening extending throughthe center of each shoulder portion 27. A bolt 28 extends through theend walls of the housing 15 and through the bore 26 and the openingwithin the shoulder 27. A spring 29 is mounted adjacent one end of thebolt betw en a collar 30 thereon and the shoulder 27, and a; spring 31is mounted adjacent the other end of the bolt between a collar 32thereon and the shoulder 27. A bushing 88 threaded in the housing isjournaled on the outer end of the bolt between the collar and bolt head34:. It will be seen that the bolt may be moved longitudinally byrotating the bushing 33.

In the position illustrated in Fig. 2, the bushing 33 is screwedinwardly thereby holding the spring 31 under compression and thefollower 23 in engagement with the cam. As thus adjusted, rotation ofthe cam will operate to draw the tool toward the rain in its relievingmovement. Such operation is used in exterior relieving wherein the L lis mounted as shown in the drawing. To reverse the relieving movementsof the tool, the bushing 33 is screwed outwardly whereby the spring 31is released and the spring 29 compressed. As thus adjusted, the follower22 will be forced into engagement with the cam and rotation of the camwill operate to force the tool away from the cam in its relievingmovements. This operation is used in interior relieving where the toolmounted to point in the opposite direction from that shown in thedrawing. Adjustable stops 35 are threaded in each end of the housing forlimiting the reciprocating movements of the block and thereby therelieving movements of the tool, shoes as being provided on the blockfor engagement with the stops.

A handle 37 is provided for holding both cam followers disengaged fromthe cam thereby releasing the mechanism from op-- eration even thoughthe cam continues to rotate. This handle is mounted on a shaft 3%), the.inner end of which carries an arm 39 provided with a stud ell) at itsfree end. The reciprocating block 21 is provided with a notched platel-l having a recess therein with anguiar sides leading into abottomportion This recess is beneath the stud sit) and rotation of the handle37 to the right will at any time move the stud into the re cess andthereby move and hold the block in a neutral position with both camfollowers disengaged from the cam. A spring pressed detent 4-3 isprovided for holding the handle in either of its two positions.

In og ieration, the work piece to be relieved is mounted on the lathecenters in the usual manner and the tool is moved up to the work bymeans of the screw 7. lt will be understood that the gearing ratiobetween the lathe spindle and the cam 19 depends upon the number ofteeth on the work piece to be relieved this ratio of course being suchthat the cam will progressively force the tool into engagement with eachtooth on the work piece as the same is retated, the springs 31 beingadapted to move the tool in the opposite direction. The cam and springstherefore operate to reciprocate the tool toward and from the work asthe latter rotates, such operation of course being synchronous with therotation of the work whereby each tooth of the work piece is cut withrelief in the well known manner. The tool must of course be positivelymoved by the cam in the cutting direction and such direction can bechanged by ad justing the bushings 33 as above described. it is believedthat the construction and op eration of the mechanism will be clearlyunderstood without further description thereof.

\Vhat I claim is:

1. In a relieving attachment for lathes. the combination of a bed, atool carriage thereon. a tool slide supported by the carriage, a rotarycam movable along the bed with the carriage, a pair of cam followers,means for giving relieving movements to the tool. slide when one or theother of the followers is engaged with the cam, and means foroperatively engaging either follower with the cam the tool slide beingadapted to be positively operated in one direction for performingexterior relieving operations when follower engaged with the cam and bis: adapted to no positively operated in the opposite direction forperforming inill! liltl terior relieving operations when the otherfollower is engaged with the cam.

2. In a relieving attachment for lathes, the combination of a bed, atool carriage thereon, a tool slide supported by the carriage, a rotarycam, a pair of cam followers on diametrically opposite sides of the cam,spring means for normally holding one or the other of the followers inengagement with the cam, and adjustable means for operatively engagingeither follower with the cam for operating the tool slide in eitherdirection for performing either exterior or interior relievingoperations.

3. In a relieving attachment for lathes, the combination of a bed, atool carriage thereon, a tool slide supported by the carriage, a rotarycam movable along the bed with the carriage, cam follower meansoperatively connected to the tool slide, spring means for normallyholding the follower means in engagement with the cam, and adjustablemeans for causing the spring means to operate on the follower means tohold the same engaged on either side of the cam whereby to operate thetool slide in either direction for performing either exterior orinterior relieving operations.

4. In a relieving attachment for lathes, the combination of a bed, atool carriage thereon, a tool slide supported by the carriage, a rotarycam on the carriage, a pair of cam followers operatively connected tothe tool slide, spring means operative on the followers, and adjustablemeans for causing the spring means to operate on either follower to holdthe same engaged with the cam for operating the tool slide in eitherdirection for performing either exterior or interior relievingoperations.

5. In a relieving attachment for lathes, the combination of a bed, atool carriage thereon, a tool slide supported by the car-- riage, arotary cam on the carriage, a block operatively connected to the toolslide and provided with means for engaging the cam, spring meansoperative on the block, and adjustable means operative on the springmeans to optionally hold the follower means en aged with either side ofthe cam whereby to operate the tool slide in either direction forperforming either exterior or interior relieving operations.

6. In a relieving attachment for lathes, the combinaton of a bed, a toolcarriage thereon, a tool slide supported by the carriage, a rotary cammovable along the bed with the carriage, a block operatively con nectedto the tool slide and supporting a pair of cam followers respectively onopposite sides of the cam, spring means operative on the block. andadjustable means operative on the spring means to optionally hold eitherfollower in engagement with the cam whereby to operate the tool slide ineither direction for performing either exterior or interior relievingoperations.

7. In a relieving attachment for lathes, the combination. of a bed, atool carriage thereon, a tool slide supported by the carriage, a rotarycam movable along the bed with the carriage, a reciprocable blockoperatively connected to the tool slide and supporting a pair of camfolowers respectively on opposite sides of the cam, adjustable means forlimiting the reciprocating movement of the block, spring means operativeon the block, and adjustable means operative on the spring means tooptionally hold either follower in engagementwith the (3am whereby tooperate the tool slide in either direction for performing eitherexterior or interior relieving operations.

8. In a relieving attachment for lathes, the combination of a bed, atool carriage thereon, a tool slide supported by the carriage, a rotarycam movable along the bed with the carriage, a block operativelyconnected to the tool slide and supporting a pair of cam followersrespectively on opposite sides of the cam, a bolt adjustable on thecarriage and extending into the block, spring means on the bolt adaptedto operate by compression on the block, the bolt being adjustable toplace the spring means under compression in either direction on theblock thereby holding one or the other follower in engagement with thecam whereby to operate the tool slide in either direction for performingeither exterior or interior relieving operations.

9. In a relieving attachn'ient for lathes, the combination of a bed, atool carriage thereon, a tool slide supported by the carriage, a rotarycam movable along the bed with the carriage, a reciprocable blockoperatively connected to the tool slide and supporting a pair of camfollowers respectively on opposite sides of the cam, a pair of springsadapted to operate in opposite directions on the block to respectivelyhold one or the other follower in engagei'nent with the cam. andadjustable means for placing either spring under compression therebyholding its follower in engagement with the cam whereby the tool slidemay be operated in either direction for performing either exterior orinterior relieving operations.

10. In a relieving attachment for lathes, the combination of a bed, atool carriage thereon, a tool slide supported by the carriage, a housingon the carriage, a rotary cam supported in the housing, a blockreciprocably mounted in the housing, connected to the tool slide andsupporting a pair of cum followers on opposite sides of the cam, a boltextending through the housing and block and a pair of springs on thebolt adapted to operate respectively in opposite ltlt) directions on theblock to hold one or the other follower in engagen'ient with the cam,the bolt being adjustable to place either spring under compressionthereby holding its follower in engagement with the cam whereby the toolslide may be operated in either direction for performing either exterioror interior relieving operations.

11. In a relieving attachment for lathes, the combination of a bed, atool carriage thereon, a tool slide supported by the carriage, a rotarycam, a pair of cam followers, spring means for normally holding one orthe other of the followers in engagement with the cam, adjustable meansfor operatively engaging either follower with the cam whereby the toolslide may be ope-rated in either direction for performing eitherexterior or interior relieving operations, and

ieans for holding both followers disengaged from the cam.

12. In a relieving attachment for lathes, the combination of a bed, atool carriage thereon, a tool slide supported by the carriage, a rotarycam, movable along the bed with the carriage, a block operativelyconnected to the tool slide and supporting a pair of cam followersreioectively on opposite sides of the cam, spring means opera-- t-ive onthe block, adj ustable means operative on the spring means to optionallyhold either follower in engagement with the cam whereby to operate thetool slide in either direction for performing either exterior orinterior relieving operations, and means optionally engageable with theblock for holding' both followers disengaged from the cam.

13. In a relieving attachment for lathes, the combination with a bed, atool carriage thereon, a former bar at the rear of the bed, a taperslide on the carriage, and a tool support on the taper slide, a housingsecured to the former bar a rotary cam supported a pair of cam followersopera-tively connected to the tool support, and adjustable means foroperatively engaging either follower with the cam for operating the toolsupport in either direction for performing either exterior or interiorrelieving operations.

H. In a relieving attachment for lathes, the combination with a bed, atool carriage thereon, a former bar at the rear of the bed, a taperslide on the carriage, and a tool support on the taper slide, a housingsecured to the former bar, arotary cam supported in the housing, a pairof cam followers operatively connected to the taper slide, spring meansoperative on the followers, and adjustable means for causing the springmeans to operate on either follower to hold the same engaged with thecam for operating the taper slide in either direction for performingeither exterior or interior relieving operations.

15. In a relieving attachment for lathes, the combination with a bed, atool carriage thereon, a former bar at the rear of the bed, a taperslide on the carriage, and a tool support on the taper slide, a housingsecured to the former bar, a rotary cam supported in the housing, ablock reciprocable in the housing and operatively connected to the taperslide, a pair of cam followers on the block at opposite sides of thecam, spring means operative on the block, and adjustable means operativeon the spring means to optionally hold either follower in engagementwith the cam whereby to operate the taper slide in either direction forforming either exterior or interior relieving operations.

In testimony whereof, I hereto afliX my signature.

AUGUST BERNHARD LINDSTROM.

in the housin

